Some motorcycles are of the type in that a front part of a motorcycle body frame is covered with a front cowling from the front to both right and left sides so as to minimize air disturbance caused by car running, thereby to reduce running resistance. The front cowling is provided on the front with a cooling air inlet port so that an engine mounted inside the front cowling is cooled by running air flowing from the inlet port.
Japanese Patent Early Laid-open Publication No. 60-146771 discloses a body cover for such motorcycles, wherein both right and left frame covers 01 and 01' with front parts thereof bent outwards generally in a U-shape, as shown in FIG. 1, are mounted on an under side of a seat 02 and with the outsides of front ends thereof held in alingment with a rear edge 04 or 04' of a front cowling 03, thereby to prevent a leg portion of a rider from hot air which has just finished its task for cooling an engine 06.
In such motorcycles as described, however, the rear edge 04 of the front cowling 03 is situated at a part where the leg of the rider who sits astride the seat 02, is abutted and thus undesirable. Moreover, cooling air flowing backwards passing through the engine 06, receives resistance from the portion 05 of the front end of the frame covers 01 and 01' which is bent generally in a U-shape. Furthermore, running air flowing along the outside of the front cowling 03, is disturbed at a portion where the outside of the front cowling 03 is discontinued at the rear edges 04 and 04' thereby to increase air resistance. In addition, in such motorcycles as mentioned, the whole front cowling 03 must be removed from the body when a maintenance is performed on the engine.